Distributor for refrigeration systems



Aug. l2, 1947. E. s. H. BAARs 2,425,452

DISTRIBUTOR FOR REFRIGERATION SYSTEMS- Filed March 15. 1943 3 Sheets-Sheet'.V 1

Aug. 12,r 1947. E. s. H. BAARS 2,425,452

DISTRIBUTOR FOR REFRIGERATION SYSTEMS Filed March 15, 194s s sneetssneet 2 /i rrofe /vf' 25'.

' Aug. 12, 1947.

E. S. rvl'l. BAARE' DISTRIBUTOR FOR REFRIGERATION SYSTEMS s' lsheets-sham. :s

Filed March 13, 1945 l .lll l 1u i! lull Patented Aug. l2, 1947 DISTRIBUTOR FOR REFRIGERATION SYSTEMS Ernst S. l-I. Baars, Milwaukee, Wis., assignor to The Vilter Manufacturing Co., Milwaukee, Wis., a corporation of Wisconsin Application March 13, 1943, Serial No. 479,029

8 Claims.

My present invention relates generally to improvements pertaining to the art of refrigeration, and relates more especially to an improved refrigerating system and to new and useful mechanism for feeding refrigerant to such systems.

The primary object of my invention is to provide an improved low temperature refrigeration system having simple and highly efficient feed mechanism for positively delivering an ample supply of refrigerant to such improved system.

Perhaps the most difficult and annoying problem in connection with the operation of low temperature refrigeration systems, is the matter of feeding fresh refrigerant to the cooling coils or other cooling elements, especially when the system involves a multiplicity of such coils or elements. Mostl of the prior feed mechanisms are thermostatically actuated and as a rule, such actuation is not sufficiently reliable and sensitive to insure requisite uniformity and abundance of feed for low temperature freezing. To my knowledge, none of the feed assemblages heretofore used in conjunction with low temperature refrigerating systems, are positive in action, and practically all of the prior mechanical feed mechanisms and feed pumps for other systems are relatively complicated and require considerable power for normal operation.

It is therefore a more specific object of the present improvement to provide an improved positive feed for delivering refrigerant to -low temperature refrigeration systems, which is accurate and sensitive in operation and which is also operable without; excessive power consumption.

Another specific object of this invention is to provide a simple and dependable feeder for high pressure refrigerant, wherein the existing high pressure is utilized to deliver the fluent refrigerant to the cooling coils, thereby avoiding necessity Vof mechanical propulsion with the aid of pumps or the like.

A further specic object of the invention is to provide an improved mechanical feed mechanism for high pressure refrigerant, which is operable with negligible power consumption to positively and effectively feed any desired number of` cooling units or coils, and to meet varying feed requirements.

Still another specic object of my invention is to provide a new and useful low temperature refrigeration system having an improved refrigerant recirculating feature whereby contact of liquid refrigerant with all portions of the cooling surfaces is assured at all times.

An additional specific object of my present invention is to provide an improved low temperature refrigerating system provided With constant differential pressure control means for maintaining a definite pressure diierential between the low pressure side of the cooling elements and the discharge side of the low pressure compressor, and which means may be regulated to meet varying conditions of operation.

These and other specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the several features constituting my present improvement, and of the mode of constructing and of operating low temperature refrigeration systems embodying the invention, may be had by referring to the drawings accompanying and forming a part of this specication wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a relatively large central vertical section through my improved positive refrigerant feeder, the section having been taken along the line I-I of Fig. 2 but the upper equalizing opening which is normally in front of the line I--I having been shown in dotted lines in order to indicate its relative position;

Fig. 2 is a somewhat reduced top view of the positive feed mechanism of Fig. 1;

Fig. 3 is a transverse horizontal section through the feed mechanisms of Figs. 1 and 2, taken along the line 3-3 of Fig. land looking down- Fig. 4 is another transverse horizontal section through the same feed mechanism, taken along the line 4-,4 ofFig. 1 andalso looking downwardly;

Fig. 5 is an irregular vertical section taken through the lower head or base plate of the feed strict the utility of all features thereof lto suchsystems.

Referring to the drawings, and more especially to Fig. 6, the improved refrigeration system shown therein comprises in general a plurality of cooling units or coils 8 having their upper inlet 3 a ends connected with a positive refrigerant supply or feed mechanism 9 bylmeans of feed pipes I0, while their lower outlet ends communicate with a low pressure accumulator or separator I I a low pressure pump or compressor. I2 having a suction line I3 communicating with the uppery most portion of the separator I, and also having a discharge line I4; a high pressure pump or compressor I5 having its suction side connected to the low pressure compressor or intermediate discharge line I4, and also having a high pressure discharge line I6 communicating with a condenser I1; a high pressure liquid refrigerant accumulator and cooler I8 communicating with the plate 21 of the mechanism 9; an adjustable con` stant differential back pressure control valve 29 interposed between' the accumulator connection 22 and the high pressure suction line I4, and being operable by variations in pressure in the suction line I3, to automatically maintain a constant and definite back pressure in the accumulator connection 22 regardless of variations in pressure in' the suction iine I4 of the high pressure compressor `|5, and regardless of changes in load; a cold liquid return pipe 29 connecting the lower-` most portion of the separator II with another passage 38in the lower base plate 21 of the mech-V anism 9; and pressure equalizing lconnections 3|, 32 connecting the separator II ywith the feed mechanism 9, and the accumulator connection 22 with the feed line 23, respectively.

While most of the individual elements or parts of the system including the coils 8, accumulator or separator II, compressors I2, I5, condenser I1, intermediate accumulator and cooler I8, float valveA I9, and the various connections, are of rel` atively standard and well known construction, their combination andassociation with the feed mechanism 9 and with the constant differential pressure valve 28 possesses advantages and produces desirable results not heretofore vobtainable 4in connection with low temperature refrigeration systems. 'I'he adjustable constant differential valve 28 is also of the ywell known type'frequently designated as an automatic back pressure valve, and is provided with adjustablesprings which may be set to `produce any desired constant pres-j sure differential. The use of such a valve in con-t junction with my positive feed mechanism, re-` which is of special construction and which permits utilization of the high pressure normally eir-` isting in the intermediate accumulator and cooler I8, in order-to insure abundant and uniform feeding of liquid refrigerant to the coils 8; and

which is moreover adapted to positively and ac-` curately deliver refrigerant to any isild m1111- ber of units or coils 8.

'I'he improved positive feed mechanism is shown in detail in Figs. 1 to 5 inclusive, and comprises a constantly rotatable cylinder or drum 33 having upper and lower closure heads 34, 35 respectively,A and being providedwith three inter-` nal radiating partitions 36 dividing the drum interior into three similar sector shaped chambers 31; a fixed cylindrical housing casing 38 enclosing the drum 33 and having upper and lower closure plates 39, 21 respectively, the former of which is provided with the feed inlet opening 24 yand with another opening 4communicatin8 with the equalizing connection 3| while the latter is provided with the passages 26, 30 and with ing 45 carried by the upper plate 39 and having a bevel driving gear 46 at its upper end while its lower end 41 is polygonal in shape and ts'within a similarly formed socket 48'formed centrally within the rotorhead 34:,and a power source suchv as an electric kmotor V49 coacting through Vspeed reducing mechanism and a bevel pinion 50 with the gear 46 so as to constantly revolve the drum 33 and heads 34,-35 at yany selected uni.

form speed within the housing casing.

lThe rotor drum 33 may be formed from a piece I of tubing welded or otherwise rigidly attached to the closure heads 3 4, 35, andthe partitions 3B may be constructed of sheet `metal likewise welded or otherwise rigidly secured to both the drum 33 and heads 34, 35. As shown in Fig. 3, the upper head 34 is provided with three equally spaced slots 5I which are periodically and successively communicable with the openings 24, 40 through passages 52 formed in the sealing ring 42; and the lower head `35 of the feed rotor is provided with a series of three equally spaced circular ports 53 which are periodically communicable with the passages26, 30 through slots 54, 55 formed in the lower plate 21 as indicated in Figs. 3 and 4.` The lower head 35 of the rotor is also provided with a series of small feed orices 56 which are so located that they will intermittently or periodical- 1y register with ports 51 formed in the lower platel 21 and which communicate with the delivery passages 4|; and while there are a number of these v, passages 4|, some of them may be sealed with' f plugs 58 while others may be connected to the feedr pipes I0 for the cooling kcoils 8, see Figs. 4, 5 and 6. The orifices 56 and ports 51 should preferably be so disposed that they willinsure uniform periodic feeding of liquid refrigerant to the coil feed lines I0 fromv the successive revolving cham-bers 31, `and while these chambers arev subjected to high pressure; and in order to retain the feed rotor in central position within the casing 38, the lower head 35 may be provided with a centering lug 59 coacting with a socket 3|! in the lower plate 21. l

The housing casing 38 may also be formed 0f a piece of tubing and .the opposite ends of this casing may bev fitted within annular recesses 3| formed in the upper and lower plates 39, 21 and clamped firmly within these recesses by means of nuts and bolts 52. 'This assemblage will retainv the parts in place against internal pressure, while permitting ready dismantling of the housingffor inspection of the feed'rotor. In order to provide a compact feed unit 3, the propelling motor 43 may be secured to a bracket 33 carried by the upper head 33, and the anti-friction bearing 45 and gears 48, 53 may also be associated with this bracket 33, see Figs. l, 2 and 6. Possible escape of refrigerant from within the housing casing and along the shaft 44, is .prevented by a special anti-friction high pressure seal shown in Fig. 1, and comprising upper and lower plates 34, 35 which are constantly urged away from each other by a spring 66, and coact with rings 31 which in turn engage packing rings 33. The springs 43 which constantly urge the annular sealing plate 42 against the upper head 34 of the feed rotor, also coact with expansible tubular corrugated sealing elements 38 disposed within the openings 24, 40, and with sealing rings 13 which engage bosses 1I formed on the plate 42. These bosses 1I in which the passages 52 are formed. are disposed approximately 180" apart and snugly but slidably engage parallel bores 12 in the upper plate 39, and the pipes 2,3, 3l are connected with their respective openings 24, 43 by means of clamping flanges 13 which also engage flanges 14 secured to the upper ends of the elements 38, thereby providing effective high pressure seals at the openings 24, 4II. This assemblage of elements prevents undesirable escape of refrigerant from the interior of the rotor into the housing casing, and from the housing casing to the arnbient atmosphere, and by spacing the exterior of the drum 3,3 from the interior of the casing 38 and providing antifriction bearings and seals wherever possible, the amount of power required to rotate or drive the feed rotor is reduced to a minimum.

The three-way constant differential pressure valve 23 which is operable by variations in pressure in the suction line I3', and is adapted to establish communication between .the accumulator I8 and the high pressure suction line I4 of the compressor I5, may be of any well known type used quite extensively in the refrigerating industry, ordinarily embodying a valve actuating piston or diaphragm coacting with adjusting springs and exposed on opposite sides to the accumulator connection 22 and to the suction line vI3 of the low pressure compressor I2. 'I'his valve 23 functions to maintain a constant or definite pressure differential between the low, intermediate and high pressure zones of the system by permitting gases from the accumulator to escape directly to the high pressure compressor I5 and thereby insures uniform feeding of the refrigerant.

During normal operation of the improved low y temperaturerefrigeration system, the motor 49 should be -operated to constantly rotate the positive feed drum 33 at the selected uniform speed, and means should be provided for varying this speed to meet requirements. The number of cooling coils 8 may alsov be increased or diminished according to requirements, and these coils should be connected to the feed passages 4I in the base plate 21 by connections III. The high pressure feed pipe 23 should be open, and when the compressors I2, I5 are operating, liquid refrigerant under high pressure will be delivered from the condenser I1 to the accumulator I8 past the float control valve I3. As the feed rotor revolves, liquid refrigerant will be periodically delivered from the accumulator I3 through the supply pipe 23 and inletopening 24 to the successive chambers 31 through the slots 5I, thus substantially filling the chambers 31 with high pressure refrigerant.

6 Some of the refrigerant thus admitted to each chamber31 is immediately discharged through the small orifices 53 to the ports 51 which communicate with the passages 4I and pipes I0 leading to the coils 8, thus admitting charges of liquid refrigerant to the cooling coils in rapid succession and at uniformly spacedintervals. The

refrigerant escaping from the coils 8 passes into the low pressure accumulator or separator II from whence cold liquid refrigerant is returned by gravity through the connection 29 to the passage 33 in the base plate 21, and as each chamber 31 is revolved over the elongated port 55 communicating with the passage 33, cold liquid refrigerant is delivered thereto and the chamber is carried forward for subsequent communication with the inlet opening 24 and with the orifices 53. While the by-pass 25 may normally be closed, the valve in this by-pass can be opened at will so as to also admit liquid refrigerant directly from the accumulator I8 to each of the successive rotor chambers 31 through the passage 26 and port 54, and an abundance of liquid refrigerant within each chamber 31 may thus be insured at all times and especially when starting the system. This by-pass 25 may also Ibe utilized to good advantage for reducing the capacity of the positive feeder, and when the valve in the by-pass is left fully open, liquid refrigerant under high pressure will flow through the successive chambers 31 and through the slots 5I and equalizer connection 3| directly to the low pressure zone of the system. This equalizer connection 3| will also serve to permit gases to escape from the chambers 31 directly to the separator II, and the differential pressure valve 28 will function to automatically maintain a denite pressure differential between the low pressure, intermediate pressure and high pressure sides of the system. The equalizer connection 32 functions to equalize the pressures-at the lower and upper ends of the accumulator `I8 and should be used primarily when the by-pass 25 is utilized, and a closed system is thus provided wherein constant recirculation of the refrigerant may be automatically effected thus maintaining the entire cooling surface in contact with an abundant supply of evaporating liquid at all times.

From the foregoing detailed description it will ibe apparent that my present invention provides an improved low temperature refrigeration system wherein the refrigerant is positively fed to thev cooling coil-s with minimum expenditure of power and in a most uniform and effective manner. The improved positive feed mechanism may obviously'be utilized to feed refrigerant to any desired number of cooling units, and the refrigerant in the system is continuously and most effectively recirculated while the feeding of the refrigerant is accomplished primarily by the high pressure within the accumulator I8. 'I'he improved system i-s moreover extremely flexible in its operation and adaptations, and the by-pass 25 may readily be utilized to vary the capacity of the cooling coils 8 and of the system. While the improved system and feed mechanisms are especially adapted for use in connection with low temperature refrigerating installations, some of the features may obviously be more generally applied to other refrigeration systems, and the improved feeder is obviously so constructed that danger of escape of refrigerant is eliminated while the feed- .er may be operated with minimum power.

It should be understood that it is not desired to limit this invention to the exact details of con- 7 struction or to the precise mode of use of the apparatus herein shown and described, for var--` ious modifications within the scope of the claims may occur to persons skilled in the art.

`Iclaim: `l. In a low temperature closed refrigeration n system. several cooling elements having their outlets connected to a low pressure zone, a pair of compressors connected in series for delivering refrigerant Afrom said low pressure zone to a high pressure zone, feed means for periodically delivering liquid refrigerant under the iniiuence of the high pressure in said high pressure zone successlvely to the inlets of said cooling elements,

and means for conducting cold liquid refrigerant directly from said low pressure zone to said feed means.

2. In a low temperature refrigeration system,`

several coolingcoils having their outlets connected to a low pressure accumulator, low andg high pressure compressors connected in series for` delivering gaseous refrigerant from said accumu lator to a high pressure condenser, a high pressure accumulator and auxiliary cooler communieating with saidvcondenser, and feed mechanism for periodically delivering liquid refrigerant to the inlets of said coils under the influence of the pressure in said high pressure accumulator.

3. In a low temperature refrigeration system,l several cooling coils having their outlets connected to a low pressure accumulator, low and high pressure compressors connected in series for delivering gaseous refrigerant from said accumulator to a high pressure condenser, a high presl 35 cating with-said condenser, feed mechanism for periodically delivering liquid refrigerant successure accumulator and auxiliary cooler communiunits, and means for returning cold liquid refrig-` erant from said accumulator directly to said 1 feeder.

8 1 a series of segregated revolving chambers and parts through which high pressure liquid refrigerant is successively delivered from the high pressure source to said units, and means for by-passing high pressure liquid refrigerant around `said parts directly from said first mentioned means to said units through said feeder chambers.

6. In a low temperature refrigeration system, several cooling units 'having their outlets connected to a low pressure accumulator, means for compressing the gasesfrom said accumulator and for vconverting the same into high pressure liquid refrigerant, a constantly rotating feeder having a series of segregated revolving chambers through which high pressure liquid refrigerant is successively deliveredfrom the high pressure source to said units, and meansfor returning cold liquid refrigerant from said low pressure accumulator directly to the successive chambers of said feeder.

7. In a low temperature refrigeration system, several cooling coils having their' outlets connected to a low pressure accumulator, low andV high pressure compressors for delivering gaseous .y

refrigerant from said accumulator to a high pressure condenser, a high pressure accumulator andA auxiliary cooler communicating with said conf denser, means for returning gaseous refrigerant 5. In a low temperature refrigeration system,

; several cooling units having their outlets connected to a low pressure accumulator, means for g compressing the gases from said accumulator and l 1 for converting the same into high pressure 4liquid q refrigerant, a constantly rotating feeder having from said high pressure accumulator directly to said high pressure compressor, and feed mechanism for periodically delivering liquid refrigerant i to the inlets of said coils under the influence of the high pressure in said high pressure accumulator.

8. In a low temperature refrigeration system, several cooling coils having their outlets connected to a low pressure accumulator. low and high pressure compressors for delivering gaseous refrigerant from said accumulator to a high pressure condenser, a high pressure accumulator and auxiliary cooler communicating with said condenser, means for returning gaseous refrigerant from said high pressure accumulator directly to said high pressure compressor, feedI mechanism for periodically delivering liquid refrigerant to the inlets of said coils under the influence of the high pressure in said high pressure accumulator, and means for returning cold liquid refrigerant directly from said said mechanism.

REFERENCES CITED The following references are of. record in the file of this patent:

UNITED STATES PATENTS Number, Namel ,Y Date 1 Re. 4,992 y Martin et-al July 16, 1872 low pressure accumulator to ERNST s. H. Blume. 

